Improvement in hot-air furnaces



Patented Oct. 31,1871.

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UNITED STATES APATENT OFFICE.

GEORGE W. WALKER, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 120,406, dated October 31, 1871; antedated October 27, 1871.

To all 'whom 'it may concern.-

Be it known that I, GEORGE W. WALKER, of Boston, in the county of Sudolk and State of Massachusetts, have invented an Improvement in Hot-Air Furnaces; and I do herebydeclare that the following, taken in connection with the drawing which accompanies and forms part of this specification, is a description ofmy invention sufficient to enable those skilled in the art to practice it.

The invention relates to the construction of hot-air furnaces with particular reference to such disposition to the lue-pipes leading from the combustion-chamber, and the hot air-pipes which pass through the dome or auxiliary chamber into which the flue-pipes lead, as shall cause all the smoke and other volatile products of combustion to pass in direct contact with or between the hot-air pipes in their passage from the fire-pot into the dome, and thence to the main flue; and my invention consists primarily in combining, with a i'lue or series of flues leading` from one side of the combustion-chamber into a flue-chamber or dome, from the opposite side of which a main flue-pipe leads, a series of hot-air pipes passing through said dome, and so arranged that all of the volatile products from the combustionchamber, in passing from the said liuc-pipes to the main iiue, shall not only impinge upon the top and bottom surfaces ofthe iiue or heat-radiating chamber or dome, but shall also impinge against the surfaces of the hotair tubes passing through the dome, the more effectually to heat the air rising through these tubes.

The drawing represents a furnace embodying the invention.

A shows the furnace in elevation. B is a horizontal section on the line x x; C, a vertical sec tion of the dome taken on the line zz. a denotes the ash-pit; b, the Ere-pot; c, the combustion or dame-chamber, the sides and top of which constitute the main heat-radiating surfaces, the air to be heated passing into the lower part of the chamber surrounding the whole furnace andbe coming heated by contact with the heatradia ting surfaces being distributed by the hot-air pipes to the rooms to be heated in the ordinary manner. Over the main combustion-chamber c is an auxiliary flue-chamber, d, the outer sides ef g of which constitute heat-radiating surfaces, ues h t' k leading 'oin the flame-chamber o into this chamber d, and conveying the flame, smoke, and other gaseous products of combustion from the fire-pot into the chamber d, from whence they escape into the main flue-pipe l. Two or more of these pipes,i k, lead into the front of the chamber d, or into one side thereof; but the pipe h leads from the rear or opposite part of the coinbustion-chamber into the rear or opposite part of the chamber d adjacent to the main iiue-pipe l. The pipe h is furnished with a damper, by opening which the volatile products of combustion escape from the llame-chamber directly into the flue Z. When this damper is closed, however, such products can only reach the ue l through the pipes i 7c and by traversing across the domechamber d. Through this chamber, in the path thus traversed by the heated gases, I carry the series of hot-air tubes m open at top and bottom and passing entirely through the dome, as seen at C. Air heated by contact with the outer surface and top of the combustion-chamber passes upward through these tubes, which, being heated by the hot currents passing around them in the chamber (l from the pipes t' k to the iiue l, i1npart their heat to the air coming in contact with their interior surfaces, thus utilizing to a great extent all the heat contained in the smoke, Ste., after their escape from the combustion-chamber on their way to the main liue. In whatever position the top plate r of the combustion-chamber is placed when the furnace is set up, Whether the flue-pipe Zleads from the side, the front, or the back of the furnace, the relative position of the auxiliary iiue-pipes L t' la, main Hue-pipe l, and hot-air tubes m remain unchanged, the tubes m always occupying such position that all the gaseous products of combustion must come into direct contact with them in passing from the flues z' k to the main flue l. Each tube m is cast integral with the upper dome-plate g, or is permanently attached to and so as to form a projection from such plate, the tube being connected to the bottom-plate by a sand-joint n. By this construction the tubes are kept from displacement, and their permanent position facilitates the setting up of the furnace. The pipe h may be simply a support for the side of the dome opposite the iiues t' k, and not a ilue, in which case it will not have any damper, but will have a stationary diaphragm extending across it.

I claim- In combination With the main combustionthe front thereof7 traversing-the auxiliary dome- K chamber c, the auxiliary dome or flue-chamber chamber and around the air-pipes m m, and esd connecting with the combustion-chamber by oarping therefrom only at the rear thereof.

pipes 7c i at and only at the front of the fire-pot, GEO. W. WALKER.

and with the main flue by a pipe, Z, at and only at the rear of the dome, the arrangement being Witnesses: such that all of the volatile products of combus- FRANCIS GOULD, tion passrfrom the main oombu sation-chamber at S. B. KIDDER. (154) 

